Integrated Process of Coal Pyrolysis with CO_2 Reforming of Methane by Dielectric Barrier Discharge Plasma

摘要

A novel method to increase the tar yield through an integrated process of coal pyrolysis with CO_2 reforming of methane by dielectric barrier discharge plasma was put forward. The pyrolysis of Shenmu (SM) subbituminous coal was carried out under different atmospheres, including N_2,H_2, and different plasmas of H_2, CH_4, CH_4/H_2, CO_2/H_2, and CH_4CO_2/H_2 (1/1/2, MG) to check the effect of the integrated process on improving the tar yield. Two kinds of coal samples, SM and Huolinhe (HLH) lignite were used in the integrated process to investigate the effects of gas 3ow rate, pyrolysis time, H2 composition in the mixed gas (CH_4/CO_2/H_2), and discharge power on product yields. The results showed that the effect of different atmospheres on increasing the tar yield generally has the following order, especially at the temperature range 400-500 °C: MG plasma > CH_4 plasma≈ CH_4/H_2 plasma ≈ CO_2/H_2 plasma > H_2 plasma > H_2 > N_2. The tar yield of SM coal pyrolysis under MG plasma at the discharge power of 40 W for 7 min is about 2.0 and 1.8 times as that under N_2 and H_2 at 400 °C, respectively.